title: Electrical impedance monitoring of photothermal porated mammalian cells.
abstract: To transfer large cargo into mammalian cells, we recently provided a new approach called a photothermal nanoblade. Micron-sized membrane pores generated by the nanoblade are surprisingly well repaired with little cell death, suggesting rapid membrane-resealing dynamics. Here, we report the resealing time of photothermal porated mammalian cell plasma membranes using an electrical impedance sensor. Cell membrane pores were generated by high-speed cavitation bubbles induced by laser pulsing of metallic microdisks on a pair of transparent indium tin oxide electrodes. Electrical responses from the sensor electrodes were obtained with a signal voltage of 500 mV and a frequency at 500 kHz. Real-time impedance measurements show that membrane resealing and impedance recovery take a surprisingly long 1 to 2 min after laser pulsing. A nonrecovering impedance shift is also detected for cells after high-energy laser pulsing. This impedance response is also confirmed by a separate experiment in which thin-film gold electrodes are used to trigger cavitation bubbles for opening transient membrane pores on cells cultured on electrodes. Overall, our study platform provides new insight for micron-sized membrane defect repair dynamics to maintain cell viability.
authors.affiliation: 1Precision and Intelligence Laboratory, Tokyo Institute of Technology, Yokohama, Kanagawa, Japan.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Yamane
authors.forename: Yi-Chien
authors.initials: YC
authors.lastname: Wu
authors.forename: Ting-Hsiang
authors.initials: TH
authors.lastname: Wu
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Toshiyoshi
authors.forename: Michael A
authors.initials: MA
authors.lastname: Teitell
authors.forename: Pei-Yu
authors.initials: PY
authors.lastname: Chiou
mesh_terms: D002462:Cell Membrane / Q000502:physiology* / Q000528:radiation effects*; D017097:Electric Impedance; D004847:Epithelial Cells / Q000502:physiology* / Q000528:radiation effects*; D006367:HeLa Cells; D006358:Hot Temperature; D006801:Humans; D007834:Lasers
keywords: cell membrane; cell surgery; impedance sensor; membrane pores; photothermal effect; pulsed laser